The present invention relates to an arrangement for a sail for sailing boats intended to connect the sail to a mast on the sailing boat by means of a number of mast track slides distributed along one edge of the sail, which are so arranged as to be connected by means of rolling devices to a track extending along the mast.
Track slides on board sailing boats for the purpose of hoisting and hauling the mainsail on a mast run in the longitudinal direction of the mast and provide a link between the aft side of the mast and the leading edge of the mainsail. The track slides are attached to the sail with a mutual spacing of ca. 1 metre along the direction of movement and in such a way as to give the lowest possible friction against the mast in order to facilitate hoisting, hauling and reefing the mainsail. Low friction has become increasingly important in view of the fact that modern sails often have a large trailing edge and full-length battens which push against the mast. The track slides also perform the function of gathering up the sail at boom height when the sail is being hauled, so that it does not fall from the mast and the sail can be stowed on the boom.
Previously disclosed systems include: Rope luff; a rope is sewn into the luff of the mainsail. This is fed into a channel on the aft side of the mast. With this old method, the sail is not gathered up as described above, but falls down onto the deck when the sail is hauled. This is one disadvantage. Another disadvantage is that very high friction is produced between the luff and the mast. The advantages are low weight, as no track slides are required, and the absence of a gap between the sail and the mast. The system is rarely encountered today, other than on dinghies and a number of smaller keeled boats intended for racing and on older boats, essentially those with a wooden mast. Sliding track slide;. this runs in a channel on the aft side of the mast and is attached to the mainsail with a shackle or is sewn in position. The advantages are low weight, low price and the fact that, due to the small height of the sliding track slides, the sail takes up minimal space when it is gathered up above the boom during hauling. The disadvantage is high friction. Ball track slide; this moves on a rail mounted on the aft side of the mast. Low friction thanks to circulating plastic balls, made of torlon(copyright), which absorb loads in all directions apart from the direction of movement. Advantage: low friction. Disadvantages: heavy, as a separate aluminium rail must be installed for the entire length of the mast. The track slides also weigh a great deal, since they are made of aluminium. It is also expensive because of the extra rail and the expensive torlon(copyright) balls. The balls are flattened under extreme loading, and the balls then crease to roll. Finally, the aforementioned system is highly affected by dirt and salt, as the balls are a close fit and roll against one another.
The track slide for a sail previously disclosed in WO 98/41446 has an attachment part in the track slide that is accommodated internally in a track integrated with the mast. An upper and a lower lateral guide roller are situated in the opening in the track in contact with the edges of the track.
In this previously disclosed solution, the only forces to be absorbed are those with a rolling function in a single direction. A sliding friction is obtained in all other directions. Sliding friction is precisely what it is wished to avoid.
The entire wheel arrangement is thus not accommodated internally in the inner accommodating space of the track, but large parts thereof are situated outside the mast where they are unprotected from the weather and wind.
Previously disclosed in U.S. Pat. No. 5,787,830 A is a ball track slide of the kind referred to in the preamble to the description in the application, although in this case a number of rows of balls run internally in a track inside the mast.
The principal object of the present invention is thus, in the first instance, to attempt to solve the aforementioned problems by simple and effectively functioning means.
The aforementioned object is achieved by means of an arrangement in accordance with the present invention, which is characterized essentially in that the aforementioned rolling devices are accommodated jointly in a channel-shaped track integrated with the mast, with the edges of which the aforementioned rolling devices are so arranged as to interact, in that a channel-shaped opening extends along the aforementioned track to permit the track slides to extend out from the aforementioned track to enable their attachment to the sail, in that the track is formed by a separate section of the rear part of the mast, and in that a vertical flange situated to either side of the opening and extending in a common direction forms a track for central support wheels.
The following features, among others, distinguish the present invention from the arrangement previously disclosed in U.S. Pat. No. 5,787,830 A:
The present invention uses wheels instead of balls with the advantages described in the description.
All the bearing elements are situated internally in the mast in a track, with the advantages that this provides.
Internal flanges absorb the lateral forces, unlike in the prior art, where the lateral forces are absorbed by the edges of the track, which must then be made very thick in order to function in practice.
The present invention operates between two walls, and not around as single wall as in the prior art.
Significant differences thus exist between the invention and the prior art, since no previously disclosed solution exhibits internal tracks for rolling devices in a mast and these permit all the bearing elements for the track slide to be situated internally in a track in the mast, rather than being located outside the mast together with the whole or half of the track slide. The rolling friction is now minimal, which facilitates handling of the sail on board the vessel.
The invention is described below as a preferred illustrative embodiment with reference to the accompanying drawings, in which
FIG. 1 shows an upper part of a sailing boat mast with the invent on applied thereto;
FIG. 2 shows a cross section through the mast with a wheeled track slide accommodated therein;
FIG. 3 shows the aforementioned wheeled track slide on a larger scale;
FIGS. 4 and 5 show a perspective view and a cross section of a sailing boat mast with a space to accommodate a wheeled track slide therein;
FIG. 6 shows a wheeled track slide viewed directly from the side;
FIGS. 7 and 8 show sectional views along the lines VIIxe2x80x94VII and VIIIxe2x80x94VIII in FIG. 6;
FIGS. 9-12 show the wheeled track slide viewed from different directions, i.e. at an angle from the front, from below with its front side shown, at an angle from behind, and from below with its rear side shown;
FIG. 13 shows an exploded view of the wheeled track slide.